1. Field of the Invention
The present invention relates to a thin film transistor array panel and a manufacturing method thereof.
2. Discussion of the Background
A liquid crystal display (LCD) is one of the most commonly used flat panel displays, and it includes two substrates with electrodes formed thereon and a liquid crystal layer interposed between the two substrates. In the LCD, a voltage is applied to the electrodes to realign liquid crystal molecules of the liquid crystal layer to thereby regulate the transmittance of light passing through the liquid crystal layer.
As one of two display panels of the liquid crystal display, a thin film transistor (TFT) display panel is used as a circuit board for independently driving pixels in the liquid crystal display. The TFT display panel may also be used as a circuit board for independently driving pixels in an organic electro luminescence (EL) display device.
The thin film transistor array panel includes a signal wire or a gate wire transmitting a scanning signal, an image signal line or a data wire transmitting an image signal, a thin film transistor connected to the gate wire and the data wire, a pixel electrode connected to the thin film transistor, a gate insulating layer covering the gate wire for insulating, and an interlayer insulating layer covering the thin film transistor and the data wire.
The thin film transistor array panel connected to the gate wire and the data wire is controlled by a driving circuit.
This driving circuit is connected to the gate wire or the data wire formed in the display area including the pixels through signal lines, and the signal lines are densely formed in a narrow region for connection along with the driving circuit.
The line interval of the gate wire and the data wire formed in the display area has a width that is determined according to the size of the pixel such that they have a larger width than that of the signal line. That is, the line interval of the signal line is increased from the driving circuit to the display area.
On the other hand, a plurality of photolithography processes are required to form the thin film transistor, however the manufacturing cost increases according to the number of photolithography processes. Accordingly, a process using three masks has been developed to reduce the number of photolithography processes.
In the three mask process, the pixel electrode is formed through a lift-off method, however the insulating layer between the signal lines must be removed in a fan-out portion where the signal lines are aggregated densely such that the interval between the signal lines must be increased.